Numerous processes are within the purview of those skilled in the art for the preparation of toners. Emulsion aggregation (EA) is one such method. Emulsion aggregation toners may be used in forming print and/or xerographic images. Emulsion aggregation techniques may involve the formation of an emulsion latex of the resin particles, by heating the resin, using an emulsion polymerization, as disclosed in, for example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby incorporated by reference in its entirety. Other examples of emulsion/aggregation/coalescing processes for the preparation of toners are illustrated in U.S. Pat. Nos. 5,278,020, 5,290,654, 5,302,486, 5,308,734, 5,344,738, 5,346,797, 5,348,832, 5,364,729, 5,366,841, 5,370,963, 5,403,693, 5,405,728, 5,418,108, 5,496,676, 5,501,935, 5,527,658, 5,585,215, 5,650,255, 5,650,256, 5,723,253, 5,744,520, 5,763,133, 5,766,818, 5,747,215, 5,804,349, 5,827,633, 5,840,462, 5,853,944, 5,869,215, 5,863,698; 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488, 5,977,210, and 5,994,020, and U.S. Patent Application Publication No. 2008/01017989, the disclosures of which are hereby incorporated by reference in their entirety.
Polyester EA ultra low melt (ULM) toners have been prepared utilizing amorphous and crystalline polyester resins as illustrated, for example, in U.S. Patent Application Publication No. 2008/0153027, the disclosure of which is hereby incorporated by reference in its entirety.
Two exemplary emulsion aggregation toners include acrylate based toners, such as those based on styrene acrylate toner particles as illustrated in, for example, U.S. Pat. No. 6,120,967, and polyester toner particles, as disclosed in, for example, U.S. Pat. No. 5,916,725 and U.S. Patent Application Publication Nos. 2008/0090163 and 2008/0107989, the disclosures of which are hereby incorporated by reference in their entirety. Another example, as disclosed in co-pending U.S. patent application Ser. No. 11/956,878 (now U.S. Pat. No. 8,137,884), includes a toner having particles of a biobased resin, such as, for example, a semi-crystalline biodegradable polyester resin including polyhydroxyalkanoates, wherein the toner is prepared by an emulsion aggregation process.
The vast majority of polymeric materials, including polymeric materials conventionally used for preparing toner compositions, are based upon the extraction and processing of fossil fuels. However, these processes lead ultimately to increases in greenhouse gases and accumulation of non-degradable materials in the environment. Furthermore, some current polyester based toners are derived from bisphenol A, which is a known carcinogen/endocrine disruptor. It is highly likely that greater public restrictions on the use of this chemical will be enacted in the future.